1. The Field of the Invention
The invention relates to a locking device with two locking elements situated in movable fashion in relation to each other, a transmission/drive unit containing such a locking device, and a method for manufacturing such a transmission/drive unit according to the preambles to the independent claims.
2. Description of the Related Art
EP 1 320 175 A2 has disclosed a drive- and/or braking device in which a brake unit is situated inside a housing that encloses an electric motor. The brake unit has a brake disc and a brake element that can be electromagnetically pressed against each other in a frictionally engaging fashion. The brake element here is attached to the housing of the electric motor in a rotationally and axially fixed fashion while the brake disc is situated in an axially movable fashion on the rotatably supported armature shaft of the electric motor.
A braking device embodied in this way has the disadvantage that a large number of tolerances must be compensated for during assembly of the drive unit because during the assembly, the brake element is preinstalled directly on the housing and the brake disc is preinstalled on the armature shaft and only after this are they assembled and adjusted in relation to each other. In addition, the frictional engagement between the two brake discs is very susceptible to wear and other influences such as dirt, carbon dust, grease, and abrasion phenomena, which is why in EP 1 320 175 A2, the housing of the electric motor also has to be sealed in a watertight, airtight, and dust-tight fashion. In addition, such a device produces relatively loud noise when actuated, which can be unpleasant to the occupants of a motor vehicle.